This invention relates to a motionless mixer for mixing two or more kinds of fluids.
In a conventional motionless fluid mixer, fluids are mixed by causing the fluids to flow into a pipe provided with a fluid passageway and having no mechanical moving parts. The motionless fluid mixers of this type are used in various fields such as in chemical plants, food industry, environmental pollution prevention technology, electronics industry, etc.
Conventionally, as motionless fluid mixers for mixing two or more kinds of fluids, there are known (1) a mixer (Japanese Patent Publication No. 8290/1969) in which a number of bent sheet-like blades are made to come into point contact in a hollow cylindrical tube and a plurality of such blades are inserted in series into a passageway so that the respective adjacent blades are connected normal to each other, (2) a motionless diffusion mixer (Japanese Patent Application Laid-Open No. 44032/1981) in which a divided passage forming corn member provided with a spiral groove and a radial groove is arranged between motionless fluid mixers of the conventional type, (3) a fluid mixer (Japanese Patent Application Laid-Open No. 101729/1983) in which a porous plate member provided with a number of slits is arranged between motionless fluid mixer elements, and (4) a fluid mixer (Japanese Patent Application Laid-Open No. 128134/1983) in which a plurality of mixing elements respectively having spiral blades and a tubular pipe formed integrally therewith are connected to each other so that the blades partition the inside of the passageway extending through the pipe to form a plurality of fluid passages, the adjacent ends of the blades of the respective adjacent mixing elements being connected at a predetermined angle.
In the mixer of the type (1), a desirable fluid mixed condition may be obtained in the turbulent flow region. However, it is necessary to increase the mixing elements in the laminar flow region (particularly in regions less than 100 Re), which adversely results in the increase of the fluid motion resistance. In addition, a mixing device having a long length and which has an increased inner volume must be used. This results in an elongation of the time in which the fluid remains in the mixing device, and for example, when mixing two liquid reaction type resins, it is impossible to use a resin having a short pot life as the resin may likely be solidified. Moreover, the mixed composition will have an unsatisfactory mixed condition, i.e. a ribbon-like or line-like mixed condition.
Although the mixer of the type (2) is an improvement of the former type mixer (1), the divided passageway forming cone member having the spiral and radial grooves has a complicated shape. This may easily establish an abnormal fluid staying portion, which results in the clogging or solidifying of the fluid passageway. A considerably high production cost will be involved, and moreover, it is impossible to mix powder-like materials.
In the mixer of the conventional type (3), the effective cross-sectional area of the fluid passageway is reduced by the location of the porous plate member, which will result in the increase of the fluid motion resistance. In addition, when the mixer of this type is used for mixing material having a high degree of viscosity, the slits of the porous plate member may be partially clogged or solidified which adversely prevents the fluid flow from being mixed. Moreover, it is also impossible to mix the powder-like materials. Finally, in the mixer of the type (4), which is an improvement of the former type (1), the mixing of the powder materials by means of the gravity drop-down method or by the mixing of the fluid (for example, a high viscosity material) in the perfect laminar flow region have not yet been completely acheived.